Investigation into the Etiology of Black Crappie Sarcoma

Abstract

Black crappie sarcoma (BCS) is a disease affecting freshwater lake systems in western Wisconsin. It manifests in the form of tumors on black crappies, Pomoxis nigromaculatus, and has been associated with other characteristics such as lesions on the flank, pectoral, anal, and caudal fins. The cause of the sarcoma and its effect on infected fish is not completely understood. Previous studies using next-generation sequencing to detect an infectious agent from tissue cultures have not been productive. The transmission route of the disease is unclear, and the lack of published information is causing a rise in concern for lake residents as BCS appears to be spreading. An analysis of the lake depth to surface area ratio suggests that size may have an effect and watershed may be a key mechanism for distributing BCS to new lakes. Using 2-D PAGE gels, we identified an altered protein profile in the tumor tissue when compared with healthy tissue and observed abnormal cells egressing from BCS lesions. These findings offer evidence of molecular and cellular changes in infected black crappies and provide a reference for additional studies of the disease.